Conventionally, there is provided an application capable of totalizing ledger sheet data stored every day and outputting the totalized data in a chart format. By outputting the data in the chart format which can easily be seen in place of a enumeration of numerals, it is possible to enhance an efficiency of totalizing activities, for instance, business transaction, sale, accounting, stock and the like. Some of the applications of this type are compatible with Web. Under the circumstances, FLASH (flash) to be plug-in software of browser is often used in the application which is compatible with the Web in order to render a chart.
In the case in which a chart is rendered with the FLASH, there is generally carried out vector rendering utilizing the LineTo function or the DrawRect function which is a method in the Graphics class. The vector rendering represents a rendering method based on a vector format expressed in parameter information about coordinates of a point and a line or face for connecting points, and is suitable for rendering a line drawing. When the vector rendering is carried out, however, a great calculating load is applied to a rendering process for forming information given as numeric data into an image by a calculation. For this reason, there is a problem in that a performance is considerably deteriorated when a large number of line drawings are rendered.
In order to avoid the deterioration in the performance, there is generally used a method of successively transferring a large number of line drawings subjected to the vector rendering onto bitmap data. For instance, in the case in which a chart formed by a large number of polygonal lines is rendered, vector rendering utilizing a method in the Graphics class is first carried out to generate a first one of the polygonal lines. The first polygonal line is transferred onto the bitmap data to form an image. Then, contents of the Graphics class are cleared to execute the same process for a second one of the polygonal lines. In the same manner, a large number of polygonal lines are rendered with the bitmap data. Thus, the contents of the Graphics class are cleared at each time to reduce rendering information. Consequently, an operating speed can be prevented from being adversely influenced irrespective of the number of the polygonal lines to be rendered.
As a bad effect caused by forming a large number of polygonal lines into the bitmap, however, there is an operational problem in that a position of a mouse cursor cannot be decided. For instance, when the mouse cursor is put on a line or a point over a chart, it is impossible to carry out an action such as a highlight display of the selected line or a label display of the selected point (a display of ledger sheet information to be original data for generating a chart or the like). The reason is that there is no conception of a line or a point over data because a chart formed into the bitmap is a single image as a whole.
There is proposed the technique for displaying an eye pattern generated in a bitmap format from sample data on a measured signal and operating a mouse to select an optional point on an eye pattern display region, thereby highlight displaying a waveform passing through the selected point (for instance, see Patent Ledger sheet 1). However, the Patent Ledger sheet 1 does not disclose a concrete method related to how to decide a position of a mouse cursor over an image formed into a bitmap. Therefore, an implementing method is unknown.    [Patent Ledger sheet 1] Japanese Laid-Open Patent Publication No. 2008-232968